Modeling of light pipes for the optimal disposition in buildings

A light pipe is an excellent solution to transport and distribute daylight into environments without or with little lighting, guaranteeing comfort inside the rooms. As stated in the literature, the evaluation of the performances of light pipes presents numerous complexities, making the work very difficult for technicians and designers. This study is aimed to present a methodology that is able to identify the potential of light pipes using indices such as daylight autonomy (DA), continuous daylight autonomy (DAc), and useful daylight illuminance (UDI). This paper presents an analysis of daylight obtained by several configurations of simple models of light pipes installed into a 5 7 5 m plant area room. All simulations are carried out in a DAYSIM environment, which allows calculating the annual availability of daylight based on a RADIANCE raytracer backward. Several daylight conditions were analyzed for different light pipe configurations, considering different pipe lengths and a variable number of light pipes. The light pipes are tested also in the horizontal position, for different orientations. The results of all the combinations were compared with the performances of a window with dimensions equal to 1/8 of the internal surface, which was in accordance with the minimum value to be guaranteed by the Italian Regulation (D.M. 5 July 1975 n. 190) for different orientations. The results indicated a difference in daylight distribution, showing a strong correlation between the percentage levels of DA and DAc with the length and number of pipes, during different periods of the year. The simulated model is strongly influenced by the aspect ratio (R = diameter/length). The results show that the illuminance levels decrease drastically, increasing the length

A new device hypothesis for water extraction from air and basic air condition system in developing countries

This work proposes a new device for air treatment with dehumidification and water recovery/storage, with possible mitigation of indoor environmental conditions. The system is based on Peltier cells coupled with a horizontal earth‐to‐air heat exchanger, it is proposed as an easy‐to-implement alternative to the heat pumps and air handling units currently used on the market, in terms of cost, ease of installation, and maintenance. The process provides the water collection from the cooling of warm‐humid air through a process that leads to condensation and water vapor separation. The airflow generated by a fan splits into two dual flows that lap the two surfaces of the Peltier cells, one flow laps the cold surfaces undergoing sensible, latent cooling with dehumidification; the other flow laps the hot surfaces and heats up. The airflow undergoes thermal pre‐treatment through the underground horizontal geothermal pipe that precedes the Peltier cells. In the water storage tank, which also works as a mixing chamber, the two air streams are mixed to regulate the outlet temperature. The system can be stand‐alone if equipped with a photovoltaic panel and a micro wind turbine, able to be used in places where electricity is absent. The system, with different configurations, is modeled in the African city Kigali, in Rwanda

Energy Independence of a Small Office Community Powered by Photovoltaic-Wind Hybrid Systems in Widely Different Climates

Hybrid renewable energy systems are an optimal solution for small energy communities’ energy supply. One of the critical issues is the strong correlation of these systems with outdoor climatic conditions. The goal is to make local communities increasingly energy independent. To this end, an in-depth analysis of the behaviour of hybrid photovoltaic (PV)–wind systems powering small office communities in 48 locations around the world characterized by widely varying climates was conducted. System sizes, assumed to be stand-alone or grid-connected, were varied, for a total of 343 system power configurations. Highest satisfied load fraction (SLF) values are obtained with a significant predominance of PV over wind; the trend is more pronounced in dry and continental climates (zones B and D according to the Köppen climate classification). The utilization factor (UF) values of 1 are rarely reached and never in the wind-only or PV-only configurations. In all climates, the grid energy interaction factor (GEIF) values of zero are never reached but come very close. The benefit-cost ratio (BCR) of grid-connected systems is significantly higher than stand-alone systems

Thermal Modeling of a Historical Building Wall: Using Long-Term Monitoring Data to Understand the Reliability and the Robustness of Numerical Simulations

Thermal modeling of building components plays a crucial role in designing energy efficiency measures, assessing living comfort, and preventing building damages. The accuracy of the modeling process strongly depends on the reliability of the physical models and the correct selection of input parameters, especially for historic buildings where uncertainties on wall composition and material properties are higher. This work evaluates the reliability of building thermal modeling and identifies the input parameters that most affect the simulation results. A monitoring system is applied to a historic building wall to measure the temperature profile. The long-term dataset is compared with the result of a simulation model. A sensitivity analysis is applied for the determination of the influential input parameters. A two-step optimization is performed to calibrate the numerical model: the first optimization step is based on an optimized selection of the database materials, while the second optimization step uses a particle swarm algorithm. The results indicate that the output of the simulation model is largely influenced by the coefficients describing the coupling with the boundary conditions and by the thermal conductivities of the materials. Very good results are obtained already after the first optimization step ((Formula presented.) while the second optimization step improves further the agreement ((Formula presented.). The parameter values reported in the datasheets do not match those found through optimization. Even with extensive optimization using an algorithm, starting with monitoring data is insufficient to identify material parameter values

Eco-Sustainable Energy Production in Healthcare: Trends and Challenges in Renewable Energy Systems

The shift from fossil fuels to renewable energy systems represents a pivotal step toward the realization of a sustainable society. This study aims to analyze representative scientific literature on eco-sustainable energy production in the healthcare sector, particularly in hospitals. Given hospitals’ substantial electricity consumption, the adoption of renewable energy offers a reliable, low-CO2 emission solution. The COVID-19 pandemic has underscored the urgency for energy-efficient and environmentally-responsible approaches. This brief review analyzes the development of experimental, simulation, and optimization projects for sustainable energy production in healthcare facilities. The analysis reveals trends and challenges in renewable energy systems, offering valuable insights into the potential of eco-sustainable solutions in the healthcare sector. The findings indicate that hydrogen storage systems are consistently coupled with photovoltaic panels or solar collectors, but only 14% of the analyzed studies explore this potential within hospital settings. Hybrid renewable energy systems (HRES) could be used to meet the energy demands of healthcare centers and hospitals. However, the integration of HRES in hospitals and medical buildings is understudied

Definition of a Protocol for the Experimental Monitoring of Rising Damp in Three Different Masonry Models with Tuff, Carparo, and Lecce Stone

This work presents a new protocol for monitoring rising damp, which is applied to three masonry models made of tuff, carparo, and Lecce stone. First, the physical characteristics of each stone were derived in the laboratory, which included porosity, imbibition, drying index, permeability, capillarity, and sorptivity. In this case, the protocol provided three columns, one for each material, consisting of five blocks. A layer of cotton tissue was interposed between columned blocks to simulate the hygroscopic behavior of a mortar, allowing a quick disassembly and reassembly of the multiblock columns for a quick weighing. The bottoms of the columns were immersed in water to a level of about three centimeters, providing a constant replenishment for the phenomena of evaporation and rising in the stone. The maximum height achieved by the rising damp depends on the characteristics of the building materials, i.e., the amount and size of pores, pore connectivity, etc. Since these materials have different physical characteristics, the objective was to quantify the rising moisture level of the three materials tested, block by block, in a controlled indoor microclimate environment. The three columns were periodically weighed, the quantity of collected water was evaluated, and a thermographic survey was performed. The results show that at the end of the test, the highest level of rising damp is reached by tuff with a height of 43 cm, followed by Lecce stone and carparo with a height of 40 cm and 21 cm, respectively. The innovation of this study is the proposal of a new flexible and easy‐to‐apply method for monitoring this phenomenon. It gives clear and numerically comparable results. Moreover, it is applicable to any type of stone, allowing the user to evaluate both the existing state and different design solutions

Folding mechanisms steer the amyloid fibril formation propensity of highly homologous proteins

Significant advances in the understanding of the molecular determinants of fibrillogenesis can be expected from comparative studies of the aggregation propensities of proteins with highly homologous structures but different folding pathways. Here, we fully characterize, by means of stopped-flow, T-jump, CD and DSC experiments, the unfolding mechanisms of three highly homologous proteins, zinc binding Ros87 and Ml153-149 and zinc-lacking Ml452-151. The results indicate that the three proteins significantly differ in terms of stability and (un)folding mechanisms. Particularly, Ros87 and Ml153-149 appear to be much more stable to guanidine denaturation and are characterized by folding mechanisms including the presence of an intermediate. On the other hand, metal lacking Ml452-151 folds according to a classic two-state model. Successively, we have monitored the capabilities of Ros87, Ml452-151 and Ml153-149 to form amyloid fibrils under native conditions. Particularly, we show, by CD, fluorescence, DLS, TEM and SEM experiments, that after 168 hours, amyloid formation of Ros87 has started, while Ml153-149 has formed only amorphous aggregates and Ml452-151 is still monomeric in solution. This study shows how metal binding can influence protein folding pathways and thereby control conformational accessibility to aggregation-prone states, which in turn changes aggregation kinetics, shedding light on the role of metal ions in the development of protein deposition diseases

Ml proteins from Mesorhizobium loti and MucR from Brucella abortus: an AT-rich core DNA-target site and oligomerization ability

Mesorhizobium loti contains ten genes coding for proteins sharing high amino acid sequence identity with members of the Ros/MucR transcription factor family. Five of these Ros/MucR family members from Mesorhizobium loti (Ml proteins) have been recently structurally and functionally characterized demonstrating that Ml proteins are DNA-binding proteins. However, the DNA-binding studies were performed using the Ros DNA-binding site with the Ml proteins. Currently, there is no evidence as to when the Ml proteins are expressed during the Mesorhizobium loti life cycle as well as no information concerning their natural DNA-binding site. In this study, we examine the ml genes expression profile in Mesorhizobium loti and show that ml1, ml2, ml3 and ml5 are expressed during planktonic growth and in biofilms. DNA-binding experiments show that the Ml proteins studied bind a conserved AT-rich site in the promoter region of the exoY gene from Mesorhizobium loti and that the proteins make important contacts with the minor groove of DNA. Moreover, we demonstrate that the Ml proteins studied form higher-order oligomers through their N-terminal region and that the same AT-rich site is recognized by MucR from Brucella abortus using a similar mechanism involving contacts with the minor groove of DNA and oligomerization

Early high-titer plasma therapy to prevent severe Covid-19 in older adults

BACKGROUND: Therapies to interrupt the progression of early coronavirus disease 2019 (Covid-19) remain elusive. Among them, convalescent plasma administered to hospitalized patients has been unsuccessful, perhaps because antibodies should be administered earlier in the course of illness. METHODS We conducted a randomized, double-blind, placebo-controlled trial of convalescent plasma with high IgG titers against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in older adult patients within 72 hours after the onset of mild Covid-19 symptoms. The primary end point was severe respiratory disease, defined as a respiratory rate of 30 breaths per minute or more, an oxygen saturation of less than 93% while the patient was breathing ambient air, or both. The trial was stopped early at 76% of its projected sample size because cases of Covid-19 in the trial region decreased considerably and steady enrollment of trial patients became virtually impossible. RESULTS A total of 160 patients underwent randomization. In the intention-to-treat population, severe respiratory disease developed in 13 of 80 patients (16%) who received convalescent plasma and 25 of 80 patients (31%) who received placebo (relative risk, 0.52; 95% confidence interval [CI], 0.29 to 0.94; P = 0.03), with a relative risk reduction of 48%. A modified intention-to-treat analysis that excluded 6 patients who had a primary end-point event before infusion of convalescent plasma or placebo showed a larger effect size (relative risk, 0.40; 95% CI, 0.20 to 0.81). No solicited adverse events were observed. CONCLUSIONS Early administration of high-titer convalescent plasma against SARS-CoV-2 to mildly ill infected older adults reduced the progression of Covid-19. (Funded by the Bill and Melinda Gates Foundation and the Fundación INFANT Pandemic Fund; Dirección de Sangre y Medicina Transfusional del Ministerio de Salud number, PAEPCC19, Plataforma de Registro Informatizado de Investigaciones en Salud number, 1421, and ClinicalTrials.gov number, NCT04479163.).Fil: Libster, Romina Paula. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Pérez Marc, Gonzalo. Hospital Militar Central, Buenos Aires; ArgentinaFil: Wappner, Diego. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Coviello, Silvina Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Bianchi, Alejandra. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Braem, Virginia. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Esteban, Ignacio. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Caballero, Mauricio Tomás. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Wood, Cristian. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Berrueta, Mabel. Hospital Militar Central; ArgentinaFil: Rondan, Aníbal. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Lescano, Gabriela Mariel. Hospital Dr. Carlos Bocalandro; ArgentinaFil: Cruz, Pablo. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Ritou, Yvonne. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Fernández Viña, Valeria Silvina. Hospital Simplemente Evita; ArgentinaFil: Álvarez Paggi, Damián Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Esperante, Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Ferreti, Adrián. Hospital Dr. Carlos Bocalandro; ArgentinaFil: Ofman, Gaston. University of Oklahoma; Estados UnidosFil: Ciganda, Álvaro. Gobierno de la Provincia de Buenos Aires. Hospital Interzonal Especializado de Agudos y Cronicos San Juan de Dios.; ArgentinaFil: Rodriguez, Rocío. Hospital Simplemente Evita; ArgentinaFil: Lantos, Jorge. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Valentini, Ricardo. No especifíca;Fil: Itcovici, Nicolás. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Hintze, Alejandra. No especifíca;Fil: Oyarvide, M. Laura. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Etchegaray, Candela. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Neira, Alejandra. Instituto de Efectividad Clínica y Sanitaria; ArgentinaFil: Name, Ivonne. Instituto de Efectividad Clínica y Sanitaria; ArgentinaFil: Alfonso, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Swiss Medical Group; ArgentinaFil: López Castelo, Rocío. Centro de Educación Médica e Investigaciones Clínicas "Norberto Quirno"; ArgentinaFil: Caruso, Gisela. Hospital Militar Central; ArgentinaFil: Rapelius, Sofía. Hospital Militar Central; ArgentinaFil: Alvez, Fernando. Hospital Militar Central; ArgentinaFil: Etchenique, Federico. Hospital Militar Central; ArgentinaFil: Dimase, Federico. Hospital Militar Central; ArgentinaFil: Alvarez, Darío. Hospital Militar Central; ArgentinaFil: Aranda, Sofía S.. Hospital Militar Central; ArgentinaFil: Sánchez Yanotti, Clara Inés. Hospital Militar Central; ArgentinaFil: De Luca, Julián. Hospital Militar Central; ArgentinaFil: Jares Baglivo, Sofía. Hospital Militar Central; ArgentinaFil: Laudanno, Sofía. Fundación Hematológica Sarmiento; ArgentinaFil: Nowogrodzki, Florencia. Swiss Medical Group; ArgentinaFil: Larrea, Ramiro. Hospital Municipal San Isidro; ArgentinaFil: Silveyra, María. Hospital Militar Central; ArgentinaFil: Leberzstein, Gabriel. No especifíca;Fil: Debonis, Alejandra. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Molinos, Juan. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: González, Miguel. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Perez, Eduardo. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Kreplak, Nicolás. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Pastor Argüello, Susana. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Gibbons, Luz. Hospital Municipal de San Isidro; ArgentinaFil: Althabe, Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Efectividad Clínica y Sanitaria; ArgentinaFil: Bergel, Eduardo. Sanatorio Sagrado Corazón; ArgentinaFil: Polack, Fernando Pedro. Provincia de Buenos Aires. Ministerio de Salud; Argentin